The present invention relates to automatic flight control means for rotary wing aircraft, and particularly to automatic flight control means for rotary wing aircraft adapted to control the flight condition by using a signal representing the difference between the ground speed of the aircraft and a set speed.
The conventional automatic flight control means for aircraft is of a type in which the aircraft is manually adjusted to a desired attitude and speed, and thereafter the control means is engaged for maintaining the manual adjusted attitude and speed. In addition, there has been considered automatic flight control means in which, by setting a desired flight speed during the operation of the control means, the flight speed of the aircraft is automatically changed to the set speed. In speed control, it is possible to control ground speed as well as to control air speed. However, since rotary wing aircraft are apt to be influenced by wind, it is difficult to perform stable ground speed control by using the well-known systems.